* Zobrazit nápovědu

This new analytical approach for high-throughput and comprehensive lipidomic analysis of biological samples using ultrahigh-performance supercritical fluid chromatography (UHPSFC) with electrospray ionization-mass spectrometry (ESI-MS) is based on lipid class separation using 1.7 μm particle bridged ethylene hybrid silica columns and a gradient of methanol-water-ammonium acetate mixture as a modifier. The method enables a fast separation of 30 nonpolar and polar lipid classes within 6-min analysis time covering six main lipid categories including fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, sterols, and prenols. Individual lipid species within lipid classes are identified based on positive- and negative-ion full scan and tandem mass spectra measured with high mass accuracy and high resolving power. The method is used for the quantitative analysis of lipid species in biological tissues using internal standards for each lipid class. This high-throughput, comprehensive, and accurate UHPSFC/ESI-MS method is suitable for the lipidomic analysis of large sample sets in clinical research.

MeSH
glycerofosfolipidy analýza MeSH
hmotnostní spektrometrie s elektrosprejovou ionizací metody MeSH
lipidy analýza MeSH
metabolomika metody MeSH
pentanoly analýza MeSH
sfingolipidy analýza MeSH
steroly analýza MeSH
superkritická fluidní chromatografie metody MeSH
tandemová hmotnostní spektrometrie MeSH
Publikační typ
časopisecké články MeSH
práce podpořená grantem MeSH

Článek

Phytoestrogens and sterols in waters with cyanobacterial blooms - Analytical methods and estrogenic potencies

Chemosphere. 2017 ; 170 (-) : 104-112. [pub] 20161205

ISSN 1879-1298
Medvik
Zdroj

Compounds with estrogenic potencies and their adverse effects in surface waters have received much attention. Both anthropogenic and natural compounds contribute to overall estrogenic activity in freshwaters. Recently, estrogenic potencies were also found to be associated with cyanobacteria and their blooms in surface waters. The present study developed and compared the solid phase extraction and LC-MS/MS analytical approaches for determination of phytoestrogens (8 flavonoids - biochanin A, coumestrol, daidzein, equol, formononetin, genistein, naringenin, apigenin - and 5 sterols - ergosterol, β-sitosterol, stigmasterol, campesterol, brassicasterol) and cholesterol in water. The method was used for analyses of samples collected in stagnant water bodies dominated by different cyanobacterial species. Concentrations of individual flavonoids ranged from below the limit of detection to 3.58 ng/L. Sterols were present in higher amounts up to 2.25 μg/L. Biological potencies of these phytoestrogens in vitro were characterized using the hERα-HeLa-9903 cell line. The relative estrogenic potencies (compared to model estrogen - 17β-estradiol) of flavonoids ranged from 2.25E-05 to 1.26E-03 with coumestrol being the most potent. None of the sterols elicited estrogenic response in the used bioassay. Estrogenic activity was detected in collected field water samples (maximum effect corresponding to 2.07 ng/L of 17β-estradiol equivalents, transcriptional assay). At maximum phytoestrogens accounted for only 1.56 pg/L of 17β-estradiol equivalents, contributing maximally 8.5% of the total estrogenicity of the water samples. Other compounds therefore, most likely of anthropogenic origin such as steroid estrogens, are probably the major drivers of total estrogenic effects in these surface waters.

MeSH
chemické látky znečišťující vodu analýza MeSH
cholestadienoly MeSH
cholesterol analogy a deriváty MeSH
estradiol analýza MeSH
estrogeny analýza MeSH
estron analýza MeSH
fytoestrogeny analýza MeSH
fytosteroly MeSH
genistein analýza MeSH
HeLa buňky MeSH
isoflavony analýza MeSH
lidé MeSH
receptory pro estrogeny metabolismus MeSH
sinice účinky léků metabolismus MeSH
sitosteroly analýza MeSH
sladká voda MeSH
steroly analýza MeSH
tandemová hmotnostní spektrometrie MeSH
voda MeSH
Check Tag
lidé MeSH
Publikační typ
časopisecké články MeSH

Článek online

Hypercholesterolémie v těhotenství: úvahy o jejich etiologii a diagnostickém významu
[Hypercholesterolemias in pregnancy: their etiology and diagnostic significance considerations]

Česká gynekologie. 2017 ; 82 (6) : 455-461.

ISSN 1210-7832
Medvik
Zdroj

Cíl studie: Analýza výskytu těhotenské hypercholesterolémie ve zdravé pražské populaci těhotných žen. Diagnostický význam necholesterolových sterolů (NCHS) – markerů syntézy a absorpce cholesterolu u zdravých pacientek s těhotenskou hypercholesterolémií k určení její etiologie. Typ studie: Retrospektivní studie. Metodika a pacientky: Ze 21 000 klinicko-biochemických výsledků zdravých těhotných pacientek byl vybrán soubor 84 pacientek s hladinou celkového cholesterolu (CCh) > 7,0 mmol/l, u kterých byly NCHS stanoveny GC/MS metodou na Finnigan MAT 120b. Klasické lipidové parametry byly stanoveny na automat. analyzátorech Beckman Coulter a Cobas. Výsledky: Medián CCh ve skupině 21 000 pacientek činil 6,8 mmol/l; LDL-Ch 4,6 mmol/l a HDL-Ch 2,2 mmol/l. Incidence hypercholesterolémie > 8,0 mmol/l činila v populaci zdravých těhotných žen 1:132 (!). V souboru pacientek byly nalezeny tyto hodnoty NCHS: lathosterol 7,8 ? 1,7 ?mol/l, desmosterol 4,7 ? 0,9 ?mol/l; campesterol 9,8 ? 2,6 ?mol/l a sitosterol 9,6 ? 3,8 ?mol/l. Byla nalezena korelace mezi latosterolem a LDL-Ch (r = 0,524) a dále s nonHDL-Ch (r = 0,565). Campesterol a sitosterol nevykazovaly korelaci s NCHS stejně jako HDL-Ch a TAG. Diskuse: Pilotní studie dokládá v naší populaci vysoké hodnoty CCh u zdravých těhotných a jejich vysokou incidenci (1:132). Analyzované spektrum NCHS napovídá, že vysoký CCh je způsoben jeho vyšší endogenní syntézou. Závěr: Výskyt těhotenské hypercholesterolémie v naší populaci je relativně vysoký a podle našich výsledků je zvýšení vyvoláno zvýšenou endogenní syntézou cholesterolu. Zvýšených hodnot CCh v těhotenství je možno využít k selektivnímu vyhledávání do té doby nepoznané familiární hypercholesterolémie a po skončení laktace k její následné léčbě.

Objective: Analysis of gestational hypercholesterolemia incidence in Prague population of healthy pregnant women. Diagnostic significance of non-cholesterol sterols as suitable markers of endogenous synthesis and intestinal absorption in etiology of gestational hypercholesterolemia. Design: Retrospective study. Patients and methods: From 21 000 healthy pregnant women set of 84 patients with blood level of total cholesterol >7.0 mmol/l where noncholesterol sterols had been analyzed by use of GC/MS method on Finnigan MAT 120b. Lathosterol and desmosterol as markers of endogenous syntesis and campesterol and sitosterol as markers for intestinal absorbtion. Classical lipid parameters have been analyzed on Beckman Coulter and Cobas analyzators. Results: The median of total cholesterol values in the set of 21 000 healthy pregnant women – 6,8 mmol/l was observed; median of LDLCh – 4.6 mmol/l and HDLCh – 2.2 mmol/l. The frequency of hypercholesterolemia values > 8.0 mmol/l 1:132 (!) was observed. The average values were for lathosterol 7.8 ? 1.7 ?mol/l; desmosterol 4.7 ? 0.9 ?mol/l; campesterol 9.8 ? 2.6 ?mol/l; sitosterol 9.6 ? 3.8 ?mol/l. The correlations of lathosterol with total cholesterol r = 0.524 as well as with non-HDLCh r = 0.35 and LDLCh r = 0.36 were observed. In campesterol or sitosterol as well as HDLCh or TAG no significant correlations have been observed. Discussion: Pilot study for gestational hypercholesterolemias in Czech population of healthy pregnant women proved the high frequency of increased levels of total cholesterol (> 8.0 mmol/l) 1:132. Increased levels of lathosterol values could explain the hypercholesterolemia in pregnancy as result of higher endogene synthesis of cholesterol. Conclusion: Relatively high frequency of hypercholesterolemia in pregnancy is caused according to our findings by increased endogenous synthesis of cholesterol via lathosterol. The highly increased values of cholesterolemia during pregnancy could be efectivelly used for detection and after ending of lactation period for further differential diagnostic and treatment of previously undiagnosed familial hypercholesterolemias.

MeSH
cholesterol analýza MeSH
desmosterol analýza MeSH
dospělí MeSH
fytosteroly terapeutické užití MeSH
hypercholesterolemie * diagnóza etiologie MeSH
hyperlipoproteinemie typ II diagnóza MeSH
interpretace statistických dat MeSH
komplikace těhotenství * MeSH
lidé MeSH
pilotní projekty MeSH
předčasný porod MeSH
retrospektivní studie MeSH
simvastatin aplikace a dávkování škodlivé účinky terapeutické užití MeSH
statiny škodlivé účinky MeSH
steroly analýza klasifikace MeSH
těhotenství MeSH
Check Tag
dospělí MeSH
lidé MeSH
těhotenství MeSH
ženské pohlaví MeSH
Publikační typ
kazuistiky MeSH

Článek online

A new method for immediate derivatization of hydroxyl groups by fluoroalkyl chloroformates and its application for the determination of sterols and tocopherols in human serum and amniotic fluid by gas chromatography-mass spectrometry

Journal of chromatography. A, Including electrophoresis and other separation methods. 2014 ; 1339 (-) : 154-167.

J Chromatogr A
ISSN 1873-3778
Medvik
Zdroj

A new method has been described for efficient derivatization of secondary alicyclic hydroxyl groups in steroids by alkyl chloroformates (RCFs). Cholesterol, an essential human sterol and a steroid precursor in eukaryotic cells, was used as a model for treatment with various RCFs in an aqueous and non-aqueous environment. While the cholesterol hydroxyl group did not react completely with any of the tested RCFs reagents in the former case, trifluoroethyl chloroformate (TFECF) or heptafluorobutyl chloroformate (HFBCF) fully converts cholesterol and related metabolites into the corresponding mixed carbonates under anhydrous conditions in seconds. The acylation reaction was combined with liquid-liquid microextraction (LLME) between isooctane and acetonitrile phase. The sample preparation requires just a stepwise addition of 50μl isooctane with 5μl of a pyridine catalyst, 100μl acetonitrile and 100μl isooctane with dissolved 5μl of the fluoroalkyl chloroformate reagent to a dried sample. The protocol developed in this study was successfully tested for GC-MS analysis of 12 important model steroids and four main tocopherols. Each analyte provided a single peak with excellent GC separation properties, well defined EI spectra containing diagnostic fragment ions suitable for their identification and quantitation. The new method was further validated for the determination of six diagnostic non-cholesterol sterols and four main tocopherols in human serum and in amniotic fluid. Satisfactory data were obtained in terms of calibration, quantitation limits (for sterols and tocopherols, 0.05 and 0.15μg/ml, respectively), within-run precision (0.9-19.5%) and between-run precision (0.2-19.0%), accuracy (82-115%) and recovery (90-110%). The validated method was successfully applied to GC-MS analysis of the analytes in woman sera and amniotic fluids and the results are well-comparable with those reported by other authors. The presented work demonstrates for the first time capability of the RCFs to derivatize alicyclic hydroxyls in steroids and tocopherols metabolites for GC-MS with excellent reaction rates, highest reaction yields, minor reagent consumption and easy conjunction with LLME methods.